C API: NULL tstate

[Patrick Stinson]

I am using sip to generate python bindings for my c++ library. sip is also 
used to generate python bindings for the Qt Gui toolkit. The PyEval_*Thread 
and PyThreadState_* seem to end up with a NULL tstate parameter at different 
points of execution when I start instantiating more complicated sip-wrapped 
widget classes along with my own multi-threaded library. At one point, I 
moved the thread creation code into python (by causing it to simply call a 
method in my library to execute the thread), and it helped a bit. 

I'm obviously not looking for help with sip, but it would be nice to get a 
general overview of what conditions cause a NULL tstate to be passed to
these 
functions. I've posted a few messages on the sip mailing list about this,
but 
the problem seems a little too biased toward the scope of this list for any 
of them to answer. 

Cheers!